Yungoos is not a Pokémon that is native to the Alola region. It was brought to the region to help deal with the explosive population of a certain other Pokémon, and now Yungoos are commonly seen around the Alola region.

The mongoose was introduced to Hawaii in the mid-19th century in an attempt to control the large rat population in the sugar cane fields. However, since then, the mongoose population has grown to large numbers without controlling the nocturnal rat population and has greatly diminished the population of ground nesting birds.[1]